Lewis & Short

trĭens, entis, m. [tres], a third part, a third of any thing.

  1. I. In gen.: cum sciemus, quantum quasi sit in trientis triente, Cic. Att. 7, 8, 3: medicaminis, Col. 12, 20, 7: ut triens ex heminā supersit, Plin. 23, 7, 68, § 133.
    Of inheritances: cum duobus coheredibus esse in triente, Cic. Att. 7, 8, 3: heredes ex triente, Suet. Aug. 101.
  2. II. In partic.
    1. A. Of coins.
      1. 1. The third part of an as, Varr. L. L. 5, § 171 Müll.; Hor. A. P. 328; Plin. 33, 3, 13, § 45; Liv. Ep. 60; 22, 10, 7; Messala ap. Plin. 34, 13, 38, § 137; Juv. 3, 267.
      2. 2. Under the later emperors, a gold coin, the third part of an aureus, Gall. ap. Treb. Claud. 17 fin.
    2. B. As a measure of interest, one third per cent. monthly, or, in our way of reckoning, four per cent. yearly: usurae, Dig. 35, 2, 3 fin.: pensiones, Lampr. Alex. Sev. 21.
    3. C. In square or long measure.
      1. 1. The third of a juger, Col. 5, 1, 11; 5, 2, 2.
      2. 2. The third of a foot in length, Front. Aquaed. 26; 38.
    4. D. In liquid measure, a third of a sextarius, i. e. four cyathi, Prop. 3, 10 (4, 9), 29; Mart. 1, 107, 8; 6, 86, 1; 9, 88, 2; 10, 49, 1.
    5. E. Among mathematicians, the number two (as a third of six), Vitr. 3, 1 med.
  3. III. Trientem tertium … id significare ait Cincius duas libras pondo et trientem, Fest. p. 363.